Agricultural feed bagging machines have been employed for several years to pack or bag silage or the like into elongated plastic bags. In recent years, the bagging machines have also been used to pack or bag compost material and grain into the elongated plastic bags. Two of the earliest bagging machines are disclosed in U.S. Pat. Nos. 3,687,061 and 4,046,068, the complete disclosures of which are incorporated herein by reference for all purposes. In these bagging machines, silage or the like is supplied to the forward or intake end of the bagging machine and is fed to a rotor or other compression means, which conveys the silage into a tunnel on which the bag is positioned so that the bag is filled. As the material is packed into the closed bag and because the closed end of the bag is stationary, the back pressure created by the feed pressure of the rotor causes the machine to move forward and to release or deploy an additional length of the bag. The packing density of the material packed in the bag is determined and controlled by a number of factors including the rate at which the bagging machine moves forward and the rate at which the silage material is packed into the bag.
Over the past several years, bagging machines and their associated tunnels have dramatically increased in size to accommodate the end-users' desire to use larger diameter bags. Tunnels for use with the bagging machines are available in a variety of widths, some of which are sufficiently large to accommodate bags having a diameter of 12 feet, 14 feet, or more. The large width of the tunnel presents a problem when the bagging machine is being transported on public roads, which normally limit those widths to approximately 102 inches (8.5 feet). Such width restrictions greatly reduce the mobility of machines with larger tunnels. The large width of the tunnel also presents a problem when the machines and tunnels are being shipped from the manufacturer to the retailer, distributor, or end-user.
Collapsible tunnels being adjustable between an operating position and a collapsed position are shown and described in U.S. Pat. Nos. 6,907,714 and 6,834,479, the complete disclosures of which were previously incorporated herein by reference for all purposes. Some embodiments of collapsible tunnels include two or more tunnel members that are movable with relation to each other. In some configurations of such collapsible tunnels, the movement of the tunnel members introduces openings between the tunnel members. The openings in the tunnel may negatively affect the bagging operation in a number of ways.